<span>Which of the following lists characteristics of a lake and NOT a reservoir A. Artificial dam, fresh water B. natural dam, filled by runoff C. earth dam, salt water D. filled by erosion, cement dam
Answer is B: natural dam,filled by runoff</span>
Answer: Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus.
so C would seems to be right.
Explanation: The energy of an electron depends on the size of the orbit and is lower for smaller orbits. Radiation can occur only when the electron jumps from one orbit to another. The atom will be completely stable in the state with the smallest orbit, since there is no orbit of lower energy into which the electron can jump.
The second law of thermodynamics states that in a reversible process, the entropy of the universe is constant, whereas in an irreversible process, such as the transfer of heat from a hot object to a cold object, the entropy of the universe increases
Explanation:
The sum of all oxidation numbers in a neutral compound is zero. The sum of all oxidation numbers in a polyatomic (many-atom) ion is equal to the charge on the ion. The oxidation number of oxygen in a compound is usually –2. The oxidation state of hydrogen in a compound is usually +1.
The oxidation state of Al in Al(OH)
4
−
x+4(+1−2)=−1
∴x=+3
The oxidation state of Mn in MnO
2
y+2(−2)=0
∴y=+4
thank u
All the conversions have a net value of 1
